mirror of https://github.com/Qortal/Brooklyn
You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
245 lines
7.2 KiB
245 lines
7.2 KiB
// SPDX-License-Identifier: GPL-2.0 |
|
/* |
|
* helpers to map values in a linear range to range index |
|
* |
|
* Original idea borrowed from regulator framework |
|
* |
|
* It might be useful if we could support also inversely proportional ranges? |
|
* Copyright 2020 ROHM Semiconductors |
|
*/ |
|
|
|
#include <linux/errno.h> |
|
#include <linux/export.h> |
|
#include <linux/kernel.h> |
|
#include <linux/linear_range.h> |
|
#include <linux/module.h> |
|
|
|
/** |
|
* linear_range_values_in_range - return the amount of values in a range |
|
* @r: pointer to linear range where values are counted |
|
* |
|
* Compute the amount of values in range pointed by @r. Note, values can |
|
* be all equal - range with selectors 0,...,2 with step 0 still contains |
|
* 3 values even though they are all equal. |
|
* |
|
* Return: the amount of values in range pointed by @r |
|
*/ |
|
unsigned int linear_range_values_in_range(const struct linear_range *r) |
|
{ |
|
if (!r) |
|
return 0; |
|
return r->max_sel - r->min_sel + 1; |
|
} |
|
EXPORT_SYMBOL_GPL(linear_range_values_in_range); |
|
|
|
/** |
|
* linear_range_values_in_range_array - return the amount of values in ranges |
|
* @r: pointer to array of linear ranges where values are counted |
|
* @ranges: amount of ranges we include in computation. |
|
* |
|
* Compute the amount of values in ranges pointed by @r. Note, values can |
|
* be all equal - range with selectors 0,...,2 with step 0 still contains |
|
* 3 values even though they are all equal. |
|
* |
|
* Return: the amount of values in first @ranges ranges pointed by @r |
|
*/ |
|
unsigned int linear_range_values_in_range_array(const struct linear_range *r, |
|
int ranges) |
|
{ |
|
int i, values_in_range = 0; |
|
|
|
for (i = 0; i < ranges; i++) { |
|
int values; |
|
|
|
values = linear_range_values_in_range(&r[i]); |
|
if (!values) |
|
return values; |
|
|
|
values_in_range += values; |
|
} |
|
return values_in_range; |
|
} |
|
EXPORT_SYMBOL_GPL(linear_range_values_in_range_array); |
|
|
|
/** |
|
* linear_range_get_max_value - return the largest value in a range |
|
* @r: pointer to linear range where value is looked from |
|
* |
|
* Return: the largest value in the given range |
|
*/ |
|
unsigned int linear_range_get_max_value(const struct linear_range *r) |
|
{ |
|
return r->min + (r->max_sel - r->min_sel) * r->step; |
|
} |
|
EXPORT_SYMBOL_GPL(linear_range_get_max_value); |
|
|
|
/** |
|
* linear_range_get_value - fetch a value from given range |
|
* @r: pointer to linear range where value is looked from |
|
* @selector: selector for which the value is searched |
|
* @val: address where found value is updated |
|
* |
|
* Search given ranges for value which matches given selector. |
|
* |
|
* Return: 0 on success, -EINVAL given selector is not found from any of the |
|
* ranges. |
|
*/ |
|
int linear_range_get_value(const struct linear_range *r, unsigned int selector, |
|
unsigned int *val) |
|
{ |
|
if (r->min_sel > selector || r->max_sel < selector) |
|
return -EINVAL; |
|
|
|
*val = r->min + (selector - r->min_sel) * r->step; |
|
|
|
return 0; |
|
} |
|
EXPORT_SYMBOL_GPL(linear_range_get_value); |
|
|
|
/** |
|
* linear_range_get_value_array - fetch a value from array of ranges |
|
* @r: pointer to array of linear ranges where value is looked from |
|
* @ranges: amount of ranges in an array |
|
* @selector: selector for which the value is searched |
|
* @val: address where found value is updated |
|
* |
|
* Search through an array of ranges for value which matches given selector. |
|
* |
|
* Return: 0 on success, -EINVAL given selector is not found from any of the |
|
* ranges. |
|
*/ |
|
int linear_range_get_value_array(const struct linear_range *r, int ranges, |
|
unsigned int selector, unsigned int *val) |
|
{ |
|
int i; |
|
|
|
for (i = 0; i < ranges; i++) |
|
if (r[i].min_sel <= selector && r[i].max_sel >= selector) |
|
return linear_range_get_value(&r[i], selector, val); |
|
|
|
return -EINVAL; |
|
} |
|
EXPORT_SYMBOL_GPL(linear_range_get_value_array); |
|
|
|
/** |
|
* linear_range_get_selector_low - return linear range selector for value |
|
* @r: pointer to linear range where selector is looked from |
|
* @val: value for which the selector is searched |
|
* @selector: address where found selector value is updated |
|
* @found: flag to indicate that given value was in the range |
|
* |
|
* Return selector for which range value is closest match for given |
|
* input value. Value is matching if it is equal or smaller than given |
|
* value. If given value is in the range, then @found is set true. |
|
* |
|
* Return: 0 on success, -EINVAL if range is invalid or does not contain |
|
* value smaller or equal to given value |
|
*/ |
|
int linear_range_get_selector_low(const struct linear_range *r, |
|
unsigned int val, unsigned int *selector, |
|
bool *found) |
|
{ |
|
*found = false; |
|
|
|
if (r->min > val) |
|
return -EINVAL; |
|
|
|
if (linear_range_get_max_value(r) < val) { |
|
*selector = r->max_sel; |
|
return 0; |
|
} |
|
|
|
*found = true; |
|
|
|
if (r->step == 0) |
|
*selector = r->min_sel; |
|
else |
|
*selector = (val - r->min) / r->step + r->min_sel; |
|
|
|
return 0; |
|
} |
|
EXPORT_SYMBOL_GPL(linear_range_get_selector_low); |
|
|
|
/** |
|
* linear_range_get_selector_low_array - return linear range selector for value |
|
* @r: pointer to array of linear ranges where selector is looked from |
|
* @ranges: amount of ranges to scan from array |
|
* @val: value for which the selector is searched |
|
* @selector: address where found selector value is updated |
|
* @found: flag to indicate that given value was in the range |
|
* |
|
* Scan array of ranges for selector for which range value matches given |
|
* input value. Value is matching if it is equal or smaller than given |
|
* value. If given value is found to be in a range scanning is stopped and |
|
* @found is set true. If a range with values smaller than given value is found |
|
* but the range max is being smaller than given value, then the range's |
|
* biggest selector is updated to @selector but scanning ranges is continued |
|
* and @found is set to false. |
|
* |
|
* Return: 0 on success, -EINVAL if range array is invalid or does not contain |
|
* range with a value smaller or equal to given value |
|
*/ |
|
int linear_range_get_selector_low_array(const struct linear_range *r, |
|
int ranges, unsigned int val, |
|
unsigned int *selector, bool *found) |
|
{ |
|
int i; |
|
int ret = -EINVAL; |
|
|
|
for (i = 0; i < ranges; i++) { |
|
int tmpret; |
|
|
|
tmpret = linear_range_get_selector_low(&r[i], val, selector, |
|
found); |
|
if (!tmpret) |
|
ret = 0; |
|
|
|
if (*found) |
|
break; |
|
} |
|
|
|
return ret; |
|
} |
|
EXPORT_SYMBOL_GPL(linear_range_get_selector_low_array); |
|
|
|
/** |
|
* linear_range_get_selector_high - return linear range selector for value |
|
* @r: pointer to linear range where selector is looked from |
|
* @val: value for which the selector is searched |
|
* @selector: address where found selector value is updated |
|
* @found: flag to indicate that given value was in the range |
|
* |
|
* Return selector for which range value is closest match for given |
|
* input value. Value is matching if it is equal or higher than given |
|
* value. If given value is in the range, then @found is set true. |
|
* |
|
* Return: 0 on success, -EINVAL if range is invalid or does not contain |
|
* value greater or equal to given value |
|
*/ |
|
int linear_range_get_selector_high(const struct linear_range *r, |
|
unsigned int val, unsigned int *selector, |
|
bool *found) |
|
{ |
|
*found = false; |
|
|
|
if (linear_range_get_max_value(r) < val) |
|
return -EINVAL; |
|
|
|
if (r->min > val) { |
|
*selector = r->min_sel; |
|
return 0; |
|
} |
|
|
|
*found = true; |
|
|
|
if (r->step == 0) |
|
*selector = r->max_sel; |
|
else |
|
*selector = DIV_ROUND_UP(val - r->min, r->step) + r->min_sel; |
|
|
|
return 0; |
|
} |
|
EXPORT_SYMBOL_GPL(linear_range_get_selector_high); |
|
|
|
MODULE_DESCRIPTION("linear-ranges helper"); |
|
MODULE_LICENSE("GPL");
|
|
|